Paper making apparatus



Nov. 20, 1934. w KELLETT PAPER MAKING APPARATUS Filed June 6, 1932 Patented Nov. 20, 1934 UNITED STATES PATENT OFFICE PAPER MAKING APPARATUS poration/of Wisconsin Application June 6, 1932, Serial No. 615,604

10 Claims.

This invention relates to a method of and apparatus for making paper.

More specifically, this invention relates to an improved arrangement by which the paper web may be transferred from the forming wire to the drying section of the paper machine.

According to the usual practice, one or more sets of press rolls are interposed between the pick-up point and the drier. This requires the use of two felts.

In heretofore used practice of transferring light weight webs from the forming wire to the pickup felt, it has been the usual practice to remove the web from the wire by means of a top couch roll. In such cases at high speed, in order to get rid of the water squeezed from the felt passing through the nip area of the lower and upper couch rolls, it is customary to groove the lower couch roll so that the water would drain ofl. In such usual arrangements, it is necessary to run the pick-up felt quite wet in order to make it lift the sheet from the forming wire, thus increasing the amount of water necessary to be removed from the sheet before entering the drying section of the machine.

The principal object of the present invention is to eliminate the need for press rolls on the forward stretch of the carrier felt, so that the other felt may be dispensed with.

It is a further object of this invention to provide a novel arrangement of pick-up felt and forming part of the paper machine whereby the paper web may be easily transferred from the forming part of the paper machine to the pickup felt at high speed.

It is a further specific object of this invention to provide in a paper machine means by which the paper web, after passing around the couch roll, may be transferred to a pick-up felt by means of suction acting through the pick-up felt and pressure acting through the forming wire.

My present improvements, in one practical and satisfactory embodiment thereof, are illustrated in the accompanying drawing, in which Fig. 1 is a diagrammatic side elevation of a Yankee type of paper-making machine embodying this invention, and

Fig. 2 is a similar view of a modification.

Referring to the drawing, 1 indicates a headbox from which the paper stock flows onto the usual forming wire 2, forming a web designated by 3. Said forming wire 2 is carried over a breast roll 4 and a couch roll 5, passing over the usual table rolls 6. After the paper web 3 on the forming wire 2 has passed around the couch roll 5,

it contacts with the pick-up felt '7 which passes between the couch roll and a suction roll 8 having the usual vacuum section 9. The structure of the suction roll 8 is merely indicated herein, but for a description of same, reference may be had to Letters Patent to Berry No. 1,679,598, dated August 7, 1928. A group of rolls 10, 11 and 12, are also so located as to; permit necessary adjustment of the felt '7 and also so that the felt will be properly directed towards the suction pick-up roll 8. From the suctiom pick-up roll 8, the web on the pick-up felt 7 passes around guide rolls 13, 14 and 15 to the suction transfer roll 16, where the web is applied and transferred to the drying cylinder 17. I 7

From the drying cylinder 17, the felt '7 is directed to a pair of wringer rolls 18 and 19, the wringer roll 18 being of the suction type, resembling in this respect the rolls 8 and 16. Said suction wringer roll 18 serves to remove from the felt excess water which it carries due to the fact that after the felt leaves the transfer roll 16, it is preferably washed by means of water sprays indicated at 20. From the top press roll 19, the felt passes to the guide rolls 10, 11 and 12, previously described.

With the arrangement described, pick up is facilitated by the suction because it pulls the sheet out of the interstices of the wire, besides extracting water from the sheet. The suction boxes of the rolls preferably are capable of angular adjustment to suit individual requirement.

The use of the three suction rolls at the pick-up point, at the transfer point, and as a wringer roll, not only eliminates the necessity of the wet press rolls and the additional felt, but also enables the machine to be operated at extremely high speeds and with great efficiency because the web is delivered to the drier with a minimum moisture content. All three suction rolls contribute and cooperate to this end.

In the modification shown in Fig. 2, I have illustrated a slightly different type of arrangement for the suction pick-up roll. According to this modification, the pick-up roll 8a is moved a 100 short distance along the underside of the wire away from the couch roll 5, and within the loop of the wire there is positioned, to cooperate with the suction pick-up roll 8a, an auxiliary couch roll 21, the position of the rolls 5, 8a and 21 being such that the forming wire 2 is curved slightly by the periphery of the suction roll 8a as said forming wire travels between the couch rolls 5 and 21. Preferably, the suction box 9a of the suction pick-up roll 8a is angularly positioned so that the 110 pick-up felt '1 is subjected to suction before it engages the web 3 on the forming wire.

In Fig. 2, I have also illustrated a further modifled arrangement for preventing any tendency of the web to fly from the forming wire due to the action of centrifugal force when the wire is operated at extremely high speeds. with this arrangement, the felt on its backward stretch does not run to the guide rolls 10, 11 and 12, but is directed to an upper guide roll 22, indicated in dotted lines in Fig. 2, so as to direct the felt to the top side of the couch roll 5 and forming wire.

The described details of construction illustrate merely selected-embodiments of the invention, the scope of which should be determined by reference to the appended claims, said claims to be construed as broadly as possible, consistent with the state of the art.

I claim as my invention:

1. In a paper machine, the combination of a forming wire, a pick-up felt, a pick-up suction roll cooperating with said felt to pick up the web from said wire, a drier, and a suction roll for transferring the web from the felt to the drier, the arrangement being such that themoisv ture content of the web and felt is substantially maintained constant in the forward reach between the pick-up and transfer points.

2. In a paper machine, the combination of a forming wire, a pick-up felt, a pick-up suction roll cooperating with said felt to pick up the web from said wire, a drier, a suction roll for transferring the web from the felt to the drier, the arrangement being such that the moisture content of the web and felt is substantially maintained constant in the forward reach between the pickup and transfer points, meansfor washing the felt in its back stretch, and a suction wringer roll for removing a substantial part ,of the wash' water, acting on said felt intermediate thewash point and the pick-up roll.

3. In a paper machine, the combination of a forming wire, a pickup felt, a pickup suction roll cooperating with said felt to pick up the web from said wire, a drier, a suction roll for transferring the web from the felt to the drier, means for washing the felt in its back stretch, and a suction wringer roll for removing a substantial part of the wash water, acting on said felt intermediate the wash point and the pickup roll.

4. In a paper machine, the combination of a forming wire, a pickup felt, a pickup suction roll co-operating with said felt to pick up the web from said wire, a drier, a suction roll for transferring the web from the felt to the drier, means for washing the web-engaging side of the felt in its back stretch, and a. suction wringer roll for removing a substantial part of the wash water,

acting on the web engaging side of said felt intermediate the wash point and the pickup roll.

5. In a paper machine, the combination of a forming wire, a pickup felt, a pickup suction roll co-operating with said felt to pick up the web from said wire, a drier, a suction roll for transferring the web from the felt to the drier, the arrangement being such that the moisture content of the web and felt is substantially maintained constant in the forward reach between the pickup and transfer points, meam for washing the web-engaging side of the felt in its back stretch, and a suction wringer roll for removing a substantial part of the wash water, acting on the web-engaging side of said felt intermediate the wash water and the pickup roll. Y

6. In a paper machine, the .combination of a forming wire, an inner couch roll around which said wire is carried, a pickup felt, an outer pickup roll positioned with its axis lower than the axis of the inner couch 'roll, co-operating with and engaging said felt to pick up the web from said wire, a drying cylinder, and a suction roll for transferring the web' from the felt to the drying cylinder, the arrangement being such that the paper web is exposed throughout the entire forward reach between the pickup and transfer points.

7. In a paper machine, the combination of a forming wire, an inner couch roll around which said wire is carried, a pickup felt, an outer pickup roll positioned with its axis lower than the axis of the inner couch roll, co-operating with and engaging said felt to pick up the web from said wire, a drying cylinder, a suction roll for transferring the web from the felt to the drying cylinder, the arrangement being such that thepaper web is exposed throughout the entire forward reach between the pickup and transfer points, means for washing the web-engaging side of the felt in its back stretch, and a suction wringer roll for removing a substantial part of the wash water and acting on the web-engaging side of said felt intermediate the wash point and the pickup roll.

8. In combination with a paper machine including a forming wire trained around a couch asuction roll contacting said web on the lower run of the forming wire after the web and wire have passed around the couch roll, means for directing the pick-up felt over the suction area of the suction roll to receive the web from the wire with the aid of suction and gravity, means including another suction roll for transferring the web on the pick-up felt to the drying section of the paper machine.

10. In combination, a paper making machine embodying a continuous foraminous member, suction means engaging the lower run of said member at a position removed from the ends of the loop, a transfer medium engaged over said suction means and pressure means inside the loop cooperating with said suction means.

WILLIAM R. KELLE'I'I. 

